OBD-II Code
P0537
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$90–$480
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0537 sets when the A/C evaporator temperature sensor (a thermistor mounted in or on the evaporator core inside the HVAC case) reports a voltage below the calibrated low threshold, which the HVAC controller interprets as an unrealistically cold evaporator or a shorted sensor.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0537 sets when the A/C evaporator temperature sensor (a thermistor mounted in or on the evaporator core inside the HVAC case) reports a voltage belo…
P0537 sets when the A/C evaporator temperature sensor (a thermistor mounted in or on the evaporator core inside the HVAC case) reports a voltage below the calibrated low threshold, which the HVAC controller interprets as an unrealistically cold evaporator or a shorted sensor. Because the controller uses this sensor to cycle the compressor and prevent evaporator freeze-up, a low-voltage fault can either disable the A/C entirely or, worse, allow the evaporator to actually freeze if the controller defaults to assuming cold.
Cheapest-first
- unplug the sensor connector (usually accessible behind the glove box or under the dash on the passenger side) and measure resistance across the thermistor at ambient temperature, comparing to spec (typically 8 to 15 kohms at 70F).
- If the resistance is shorted or way off, replace the sensor; if the resistance is correct, the fault is in the wiring or the HVAC controller's analog input.
- Caveat: many of these sensors are physically inserted into the evaporator fins and require partial dash or HVAC case disassembly.
Vehicle-specific patterns2006-2012 GM full-size trucks and SUVs (Silverado, Tahoe, Yukon, Suburban) see the evaporator temp sensor fail from condensate corroding the pigtail,…
- 2006-2012GM full-size trucks and SUVs (Silverado, Tahoe, Yukon, Suburban) see the evaporator temp sensor fail from condensate corroding the pigtail, often combined with a blend door actuator failure that produces the same no-cold-air complaint.
- 2007-2013Ford F-150 and Expedition see the sensor itself fail and frequently get misdiagnosed as a low-charge complaint.
- 2008-2014Dodge Ram and Durango have a known issue where the sensor wire chafes against the HVAC case.
- 2010-2015Hyundai Sonata, Santa Fe, and Kia Sorento fail at the sensor connector from cabin humidity.
Estimated repair$90 to $480.
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